/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.validator.routines;
import java.text.DecimalFormat;
import java.text.Format;
import java.math.BigDecimal;
/**
* <p><b>Percentage Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).</p>
*
* <p>This is one implementation of a percent validator that has the following features:</p>
* <ul>
* <li>It is <i>lenient</i> about the the presence of the <i>percent symbol</i></li>
* <li>It converts the percent to a <code>java.math.BigDecimal</code></li>
* </ul>
*
* <p>However any of the <i>number</i> validators can be used for <i>percent</i> validation.
* For example, if you wanted a <i>percent</i> validator that converts to a
* <code>java.lang.Float</code> then you can simply instantiate an
* <code>FloatValidator</code> with the appropriate <i>format type</i>:</p>
*
* <p><code>... = new FloatValidator(false, FloatValidator.PERCENT_FORMAT);</code></p>
*
* <p>Pick the appropriate validator, depending on the type (i.e Float, Double or BigDecimal)
* you want the percent converted to. Please note, it makes no sense to use
* one of the validators that doesn't handle fractions (i.e. byte, short, integer, long
* and BigInteger) since percentages are converted to fractions (i.e <code>50%</code> is
* converted to <code>0.5</code>).</p>
*
* @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
* @since Validator 1.3.0
*/
public class PercentValidator extends BigDecimalValidator {
private static final PercentValidator VALIDATOR = new PercentValidator();
/** DecimalFormat's percent (thousand multiplier) symbol */
private static final char PERCENT_SYMBOL = '%';
private static final BigDecimal POINT_ZERO_ONE = new BigDecimal("0.01");
/**
* Return a singleton instance of this validator.
* @return A singleton instance of the PercentValidator.
*/
public static BigDecimalValidator getInstance() {
return VALIDATOR;
}
/**
* Construct a <i>strict</i> instance.
*/
public PercentValidator() {
this(true);
}
/**
* Construct an instance with the specified strict setting.
*
* @param strict <code>true</code> if strict
* <code>Format</code> parsing should be used.
*/
public PercentValidator(boolean strict) {
super(strict, PERCENT_FORMAT, true);
}
/**
* <p>Parse the value with the specified <code>Format</code>.</p>
*
* <p>This implementation is lenient whether the currency symbol
* is present or not. The default <code>NumberFormat</code>
* behaviour is for the parsing to "fail" if the currency
* symbol is missing. This method re-parses with a format
* without the currency symbol if it fails initially.</p>
*
* @param value The value to be parsed.
* @param formatter The Format to parse the value with.
* @return The parsed value if valid or <code>null</code> if invalid.
*/
protected Object parse(String value, Format formatter) {
// Initial parse of the value
BigDecimal parsedValue = (BigDecimal)super.parse(value, formatter);
if (parsedValue != null || !(formatter instanceof DecimalFormat)) {
return parsedValue;
}
// Re-parse using a pattern without the percent symbol
DecimalFormat decimalFormat = (DecimalFormat)formatter;
String pattern = decimalFormat.toPattern();
if (pattern.indexOf(PERCENT_SYMBOL) >= 0) {
StringBuffer buffer = new StringBuffer(pattern.length());
for (int i = 0; i < pattern.length(); i++) {
if (pattern.charAt(i) != PERCENT_SYMBOL) {
buffer.append(pattern.charAt(i));
}
}
decimalFormat.applyPattern(buffer.toString());
parsedValue = (BigDecimal)super.parse(value, decimalFormat);
// If parsed OK, divide by 100 to get percent
if (parsedValue != null) {
parsedValue = parsedValue.multiply(POINT_ZERO_ONE);
}
}
return parsedValue;
}
}